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XX XX XXXXX XXXXXXX XXXXXX XX XXXXX XX XX XX XX XX XX XX X XX XX XX XX XX XX XX XX XX XX XX XXXXX XXXXXX XXXXXX XXXXX XX XX XX XX XX XX XX XX XX XX XX XX XX XX XX XX XXXXX XXXXX XXXXXXX XX XX XXXXX XX XX XXXXX XX XX XX XX XXXXX XX XXX XXX XX XX XXX XX XX XX XX XX XX XXXXXXX XX XX XXXX XX XX XX XX XX XX XX X XX XXXXXXX XXXXXXX XX XX XXXXXXX XX XX XX XX XX XX XXXX XX XX XX XX XX XX XX XX XX XX XXX XX XX XX XX XX XX XX XX XX XX XX XXXXX XX XX XXXXXXX NAVPROGseven Aircraft Navigation & Flight Planning for the IBM Personal Computer, the Hewlett-Packard Vectra, and other IBM PC compatibles. ===================================== Version F.03.02 HDOS Version A.01.01, Heathkit H-8, H-89 (c) Copyright 1982 Alan Bose CP/M Version B.01.01, Heath/Zenith H-89, Z-90 Version C.02.01, Hewlett-Packard HP-120, HP-125 (c) Copyright 1982, 1984 Alan Bose and Glen Hassebrock MS-DOS Version D.03.03, Hewlett-Packard HP-150 Touchscreen Version E.03.02, Hewllet-Packard HP-110 Portable (c) Copyright 1984, 1986 Alan Bose PC-DOS Version F.03.02, IBM PC and compatibles (c) Copyright 1986, Alan Bose and Bruce Carson 1 TABLE OF CONTENTS ================= Introduction . . . . . . . . . . . . . . . . . . . . . . . 3 User-Supported Software . . . . . . . . . . . . . . . 6 Installation . . . . . . . . . . . . . . . . . . . . . . . 8 Disc Layout . . . . . . . . . . . . . . . . . . . . . 9 Start Running . . . . . . . . . . . . . . . . . . . . 9 Airport/Navaid Data Entry . . . . . . . . . . . . . . . . 10 Update Mode . . . . . . . . . . . . . . . . . . . . . 13 Aircraft Data Entry . . . . . . . . . . . . . . . . . . . 14 Navigation -- Preparing a flight. . . . . . . . . . . . . 15 Automatic Route Preparation . . . . . . . . . . . . . . . 17 Pre-Planned Routes. . . . . . . . . . . . . . . . . . . . 18 Data File Listings. . . . . . . . . . . . . . . . . . . . 18 Program Specs . . . . . . . . . . . . . . . . . . . . . . 19 NAVPROGseven / Contents Page 2 An Introduction to NAVPROGseven Aircraft Navigation & Flight Planning ===================================== (c) Copyright 1982, 1984 Alan Bose 1224 Allison Lane Schaumburg, IL 60194 Past-President, Taildragger Flyers, Inc. Chicago Rep, Aviation Safety Institute NAVPROGseven is a series of ten programs designed to prepare a flight log that is ready for use in the cockpit. NAVPROGseven stores data about each aircraft you fly and each checkpoint you fly over, and saves that information for subsequent flights. The features and functions of NAVPROGseven include: 1). Easy input & revision of the airport/navaid data base. 2). Two RNAV functions to provide latitude and longitude of a location based on fixes taken from known points. 3). Aircraft performance data stored for each of the planes you fly. 4). Easy access and display of checkpoint information as you plan your route of flight. Automatic flight planning selects navaids closest to your great circle route and plots several alternate routings. Often flown routes can be stored for later use. 5). Great circle navigation between checkpoints using aircraft performance data, and printout of a ready-to- use flight log. 6). Climb/descent profiles based on aircraft performance data. 7). Multiple sort criteria to organize airport/navaid data into easy-to-use printout. The NAVPROGseven program uses the latitude and longitude of your checkpoints to calculate the heading required for a great circle (the shortest distance between two points around a sphere). The printed flight log tells you the field elevation at your departure and destination points, navaid frequencies enroute, distances for each leg and total remaining, true and magnetic course, magnetic heading corrected for wind and magnetic variation, groundspeed corrected for climb and/or cruise & wind, ETE & ETA for each leg, fuel usage based on cruise or climb during the leg with startup/taxi/takeoff fuel accounted for, fuel remaining, and a warning if reserves will be less than VFR or IFR minimums. NAVPROGseven / Introduction Page 3 In addition a synopsis of the flight tells you fuel used, reserves in gallons and time, fuel/time/distance used to climb, and how far from your destination you should begin your descent and how fast your descent should be to maintain a gentle 2 degree descent gradient based on the groundspeed of your last leg. The descent profile assumes that you will be holding cruise airspeed during descent. The printed flight log has distance and true course of each leg conveniently arranged for easy entry into your aircraft navigation computer, if used. Or it provides a very useful flight log as you cross-check with your E6B in flight. You should note that NAVPROGseven is designed for the mid-latitudes of the northern hemisphere over distances normally associated with light aircraft. For European pilots, most functions have been designed to operate east and west of the Prime Meridian. The seed that started this series of programs was NAVPROG version 14.4 by Leland Young and his article on great circle navigation in the February 1980 issue of Microcomputing Magazine. Additional source material includes "Dutton's Navigation & Piloting" (U.S. Naval Institute, Annapolis) and the "VNR Encyclopedia of Mathematics" (Spherical trigonometry, Gellert/ Kustner/Hellwich/Kastner). NAVPROGseven was initially written & tested over a span of eighteen months and was introduced in early 1982 for the Heathkit H-89 computer using the HDOS operating system. In mid-1982 it was converted to CP/M by Glen Hassebrock. Both versions have been in use by hundreds of pilots who purchased the original programs through the Heath Users' Group. I am indebted to the many pilots who have offered their comments, suggestions and ideas over the years. Though technically a great circle route would involve constantly changing your heading during each leg, NAVPROGseven gives you a single heading for each leg that closely approximates a great circle -- just as a single heading taken 'mid-leg' from your Sectional or WAC chart will also approximate a great circle. (Your ruler's straight, it's the chart that's curved). Needless to say, it is vitally important that you always double and triple check your input. And although the system makes planning a cross-country flight quicker and easier, you should always question and verify your output. And it is nothing more than good navigating practice to cross-check your position at frequent intervals during the flight -- don't go charging off blindly, always question. NAVPROGseven / Introduction Page 4 The fate of the Air New Zealand 747 guided unerringly towards an Antarctic mountain bears a sober reminder that the most technologically advanced airplanes in the world are still subject to human error, whim and fancy. There is no replacement for common sense, no matter what 'the computer' says. Of course, it is recommended that you 'test fly' the program before you put it to actual use. Although it works well for the planes I fly, you should make sure that the output you get is within reason for your aircraft. Needless to say, there are many variables to a flight that this program simply does not, and cannot, take into account. Alan Bose 1224 Allison Lane Schaumburg, IL 60194 NAVPROGseven / Introduction Page 5 *********************************************************** * USER SUPPORTED SOFTWARE * *********************************************************** * The User-Supported Software of the Contributed Software * * Library is provided by INTEREX, the International * * Association of Hewlett-Packard Computer Users, as a * * service to its members for the purpose of fostering the * * exchange of ideas and to enhance their usage of * * Hewlett-Packard equipment. * * * * The author of a user-supported program freely * * distributes his work, and requests that users who find * * the program useful and of value, send the author a * * suggested contribution (NAVPROGseven: $45). Unlike * * conventional software, the user is able to evaluate the * * software fully before spending any money. In return * * the author may send contributing users additional * * material such as printed documentation, source code and * * most importantly, notification of patches, bugs and * * upgrades. The system depends on the active * * participation of the user community, for without a flow * * of contributions for deserving programs, authors will * * soon abandon this worthwhile method of distribution. * * * * Since these programs are subject to unlimited copying * * and distribution the prospective user is hereby put on * * notice that the programs may contain or develop faults * * the consequences of which INTEREX in general and the * * author in particular cannot be held responsible. The * * prospective user is, by virtue of obtaining and using * * these programs, assuming full risk for any and all * * consequences. * *********************************************************** * These programs were developed and tested on version * * 2.01 of the Microsoft MS-DOS operating system (HP BIOS * * A.01.02) and Microsoft Basic version 5.28, as * * distributed by Hewlett-Packard. * * * * The author cannot predict that the programs will * * perform on future versions of MS-DOS and Basic. * * However, if a version dependent program surfaces, the * * author may make available to contributing users any * * fixes and upgrades. Individual attention to problems * * of this nature is not possible with a group as large as * * INTEREX, and is left to the sole discretion of the * * author. * *********************************************************** NAVPROGseven / Introduction Page 6 *********************************************************** * NAVPROGseven is a copyrighted program, and is intended * * for your private, non-commercial use only. USER * * ALTERATIONS AND MODIFICATIONS MAY NOT BE RE-DISTRIBUTED * * WITHOUT PRIOR WRITTEN PERMISSION FROM THE AUTHOR. This * * includes conversions of the programs to operated on * * other computer brands. * * * * If you find this program a useful and valuable addition * * to your software library, the suggested contribution is * * $45 (US), sent to Alan Bose, 1224 Allison Lane, * * Schaumburg IL 60143. Contributing users will receive * * the 21-page NAVPROGseven Users Manual, the complete * * source listing, notification of upgrades, and if * * desired, a copy of the source code in ASCII format. * * (include a blank 5.25 inch disc with your check). * * * * Fresh copies of the distribution software may be * * obtained by sending a blank 5.25 inch disc and a self- * * addressed stamped return mailer to the address above. * *********************************************************** * Conversion and testing for the IBM Personal Computer * * using PC-DOS and BASICA by Bruce Carson. The IBM-PC * * conversion has also been tested on the IBM PCjr and the * * Hewlett-Packard Vectra (IBM compatible). The system * * should work on most other IBM compatibles. * *********************************************************** NAVPROGseven / Introduction Page 7 INSTALLATION ============ NAVPROGseven is designed to operate on a dual-drive system with 256K of memory using PC-DOS and BASICA. Format a PC-DOS disk and install on it a copy of BASICA. This will be your program disk. You may also make this disk capable of cold booting by including the operating system when you format the disc. Place the distribution disc on drive A: and your blank program disc on the B: drive. At the PC-DOS A> prompt type LOADPROG to copy the required program files to your working program disc. Format a second disk for data. When done, get to the PC-DOS A> prompt. Place the distribution disc on drive A: and your blank data disc on the B: drive. Type LOADDATA to copy the required data files to your working data disc. SINGLE DRIVE OPERATION You may include both programs and data files on a single disc, especially with either Double-Sided, Double-Density drives, or a Winchester drive. Optionally, you may wish to format a second disk for data alone. The batch files, LOADPROG.BAT and LOADDATA.BAT are provided to facilitate copying the program and data files. Again, all files may reside on a single disc if you so choose and have adequate discspace. Use any text editing program to alter the LOADPROG.BAT and LOADDATA.BAT batch files to meet your needs during installation. The IBM PC version of NAVPROGseven is set by default to look for the program files on drive A:, and for the data files on drive B:. An optional file NAVDISCS.DAT alters this flow. If you wish to locate your programs and data on other drives, edit NAVDISCS.DAT as required -- the first line refers to the PROGRAM FILE drive, the second line refers to the DATA FILE drive. See below for a list of which files are required on each drive. To be operational, NAVDISCS.DAT must reside on the default drive as you run NAVPROG from the PC-DOS prompt. NAVPROGseven / Installation Page 8 When you have completed the installation your 'working discs' should contain the files shown below: PROGRAM DISK (for use on drive A:, or as specified in line 1 of file NAVDISCS.DAT) (CONFIG .SYS) operating system optional BASICA .COM your BASICA interpreter NAVDISCS.DAT Optional program & data drive specs DISKAID .DAT disc identification NAVPROG .BAT PC-DOS batch file README .DOC general documentation NAVMENU .BAS the main menu program AIRINPUT.BAS input/revise airport & navaid data AIRCRAFT.BAS input/revise aircraft data AIRROUTE.BAS manual route preparation OLDROUTE.BAS retrieve a stored flight routing NAVPROG7.BAS navigation & flight log AUTONAV .BAS automatic route selection RNAVREF .BAS navaid bearing cross checks AIRALPHA.BAS database listings DATA DISK (for use on drive B:, or as specified in line 2 of file NAVDISCS.DAT) DISKBID .DAT disc identification LOADDATA.BAT batch file to initialize data disc N73116 . sample aircraft data -- DELete manually or N81259 . using program after you experiment AIRINDEX.RND { over 100 checkpoints already on file, AIRPORTS.RND { can be revised from the program, { or DELete these two & start over. ROUTINGS.DAT sample index of routes on file. Update using program only. BEHLUK .GSH sample routes on file. LUKBEH .RID Update using program only. X06C1H2 .JOT X1H206C .MTO RUNNING NAVPROGseven ==================== Place your program disc on the A: drive and your data disc on the B: drive (if not using a NAVDISCS.DAT file), or on the drives specified in the NAVDISCS.DAT file (see above). When NAVPROGseven starts running it will check that the proper discs are accessable on the proper drives. If not the program will stop and request them before continuing. You may run NAVPROGseven at the PC-DOS A> prompt by simply typing the word 'NAVPROG' followed by a carriage return. Note that the carriage return is not required for any 'one- key responses' such as <Y>es, <N>o, <E>ast, <W>est or when selecting numbers from the menu. NAVPROGseven / Installation Page 9 INPUTTING AND UPDATING AIRPORT/NAVAID DATA ========================================== Note that the carriage return is not required for any 'one- key responses' such as <Y>es, <N>o, <E>ast, <W>est or when selecting numbers from the menu. All facilities are identified by their FAA identifier, or if one is not assigned, feel free to make one up. Identifiers are usually 3 letters for navaids, 3 or 4 characters for airports, 2 letters for ILS compass locators, and a name or pseudo-word (usually 5 letters) for airway intersections and reporting points. NAVPROGseven uses up to 5 characters for checkpoint identifiers. You don't have to worry about duplicating identifiers because NAVPROGseven accepts them as normal. For example, DPA is the identifier for DuPage County Airport, near Chicago, but DPA is also the identifier for DuPage Vortac located 4.3 nm to the west. Since the vortac is not at the airport I made separate entries for each. When asked for DPA the computer will find both and ask which one you want, the airport or the navaid. (See notes on co-location below). During new data input the computer will ask for the following: FACILITY CODE: What one would expect to find there. You can make up your own but 'V' and 'N' (VORs & NDBs) have special significance since you'll be asked to enter the frequency in the next step. Notes about facility code: Plotting a great-circle route over short distances (less than a nautical mile or so) can exceed the limits of the trigonometric functions available under Basic. I've talked with the writers of other nav programs for other micros, and they've run into the same problem. When you're working on a global or continental scale, 1 or 2 miles from checkpoint to checkpoint is very small indeed. NAVPROGseven has a provision that seems to handle this dilema quite nicely. You'll notice that the Facility Code field has space to enter 2 codes, not just one -- what the FAA refers to as 'co-located' facilities. In my database I have used 'AV' to indicate a VOR located at or near an airport, or 'AN' for an airport & NDB, etc. If the navaid is within 3 or 4 miles of the airport, I still consider them co-located, and enter the latitude and NAVPROGseven / Airport & Navaid Data Page 10 longitude of the NAVAID. At that distance the airport should be in sight when flying VFR. On an IFR flight, approach plates would be in use for this final approach phase. In either case, you shouldn't be looking at your flight log. FREQUENCY: If you entered a 'V' or 'N' above, you will then be asked the frequency of the navaid -- otherwise this step is skipped. If the facility is not a navaid but you want to have a communications frequency listed, you can enter it later using the update mode, though I find it less confusing to know that all frequencies shown on the printout are NAV frequencies rather than mixing NAV & COM. NAME: Whatever you would like to call the checkpoint, navaid or airport. Be sure, however to include the state or province since the sorting program will separate that out of the name to organize all of your data into a nice, neat printout by state. The state must be preceded by a comma, or a comma and a space, such as ', MI' for Michigan or ',IL' for Illinois. I've chosen to use the postal code abbreviations because they're short, but AR is Arkansas, not Arizona which is AZ; and I don't know if I'll ever keep Michigan (MI), Missouri (MO), Mississippi (MS), Minnesota (MN) and Monatana (MT) straight, not to mention Massachusetts (MA), Maine (ME), and Maryland (MD). The code you use doesn't matter as long as you're consistant. LATITUDE & LONGITUDE: Take this from your charts, the Airport/Facility Directories, or AOPA's Airports USA. Or you can use the pseudo- RNAV function to calculate the latitude and longitude of an intersection or a landmark based on the distance and bearing from a navaid you already have on file, or based on the bearings from two navaids (like you do in the air). Note that coordinates are entered as degrees, minutes, and seconds; while they are stored internally and displayed in degrees, minutes, and tenths of a minute format. When entering longitude you will be prompted to specify east or west longitude. Since west longitude is the default, North American pilots may simply hit a carriage return. European pilots should specify east or west longitude as required. NAVPROGseven / Airport & Navaid Data Page 11 When using the RNAV functions to calculate latitude and longitude, make sure the navaid(s) are in range. When using two navaids you should remember basic navigation procedures: if you draw a line between the two navaids, the closer you are to that line the worse your accurracy. And if you are on the line it is impossible to determine your position! It is best if the two navaids are about 30-60 degrees (or 120-150 degrees) apart. The accuracy of the RNAV functions can only be as accurate as your charts and the measurements you take. Since magnetic variation changes from year to year, it is best if you use true bearings for entry. With care the typical RNAV error should be less than one nautical mile. Use the latitude and longitudes published in the Airport/Facility Directory whenever possible. Also, it's wise not to use a point calculated with RNAV to calculate another point with RNAV as any errors will be cumulative. Notes on RNAV: The pseudo-RNAV calculations with bearings approaching due east or due west can strain Basic's accuracy as several trigonometric functions approach infinity. While normally still within the tolerance of VOR equipment, you should be aware that such discrepancies can exist under certain conditions, since NAVPROG may err in one direction while your VOR may err in the other. These cross-bearings are intended to be a handy reference for the VFR pilot who doesn't have air-borne RNAV equipment. If you have onboard RNAV capability you should ALWAYS enter waypoints into your equipment from published sources. European pilots: The RNAV functions mentioned here are not currently supported east of the Prime Meridian. MAGNETIC VARIATION: Read straight from your chart. Be aware that magnetic variation changes slightly from year to year. The flux goes one way then the other over a cycle of about 10-15 years. Science has several theories why the earth's magnetic field seems to wander, but the important thing to know is that small discrep- ancies in the magnetic course and magnetic heading calculations will become evident over a period of time. The only solution is to update the magnetic variation for each entry in your database on a periodic basis. RNAV calculations are also affected by this constant shifting of magnetic variation. NAVPROGseven / Airport & Navaid Data Page 12 ELEVATION: Right from your chart if it's an airport. Navaid elevations can be found in the Airport/Facility Directory. Elevations at other locations can be approximated from your charts. Notes on elevation: The primary use for the elevation in the program is for airports. It is used to calculate your departure climb to altitude and the descent to your destination airport. If you choose to enter the elevation of navaids (which are given in the Airport/Facility Directory) the program will give a cursory check to see that your selected cruise altitude and climb/descent profile will clear the navaid. UPDATE MODE =========== In the UPDATE mode you can revise the data on file as often as you like. You can delete unneeded entries or let your library of checkpoints continually grow. In the update mode entering a 'D' for the Ident will delete the entire entry -- erasing its subsector from the index & master file. Later, when you add new data, the program searches for any 'holes' left by a deletion and fills them in first. If a hole can't be found, the new data is added to the end of the file. To maximize disc space it is best you delete unwanted entries before adding new ones. Of course airports do close, navaids are decommissioned, moved, renamed or frequencies re-assigned. NOTAMS (Notices to Airmen) are an excellent way to assure that your database is current and up-to-date. NOTAMS are published every 14 days and subscriptions are available from the U.S. Government Printing Office, Washington, DC 20402. The Aiport/Facility Directories are published every eight weeks by the National Oceanic and Atmospheric Administration National Ocean Survey Riverdale, MD 20840. AOPA's Airports USA is published yearly for members of the Aircraft Owners & Pilots Association 421 Aviation Way Frederick, MD 21701 NAVPROGseven / Airport & Navaid Data Page 13 AIRCRAFT DATA ============= When you enter your aircaft N-number the the performance data is read from the file, or if it can't be found you'll be asked to enter data from your Aircraft Operations Manual. The program takes into account fuel used for startup/taxi/takeoff, fuel/time/distance to climb to your normal cruise altitude, fuel comsumption, fuel-on-board, true airspeed, and the cost per hour to operate the plane. When entering your 'standard' cruise performance you might consider that optimum altitude for a normally aspirated engine at 75% power is in the 6-8000 foot range; giving the highest true airspeed for fuel burned. As the power setting is cut, the 'optimum altitude' increases. In actual flight, however, the winds aloft and the time & fuel used to climb there will probably effect efficiency more than optimum altitude. Also remember that flight at 75% power uses an average of 13% more fuel for only a 6% increase in speed over a flight at 65% power, while flying at 55% power uses 25% less fuel with only a 12% speed loss when compared to a flight at 75% power. It should be noted that in calculating your climb to altitude NAVPROGseven uses a straight line average based on the standards you enter here about your aircraft. Long, extended climbs at gross weight to higher altitudes than your 'standard' entered here may consume significant amounts of additional fuel. But I'm not telling you anything new, huh? Consult your Aircraft Operation Manual, please. Also, the 'standard cruise' speed & fuel consumption you enter here is guaranteed to vary on each flight depending on altitude, temperature, etc. However when each flight is calculated you will have the opportunity to enter 'non-standard' cruise parameters that will be used for that given flight. Every plane is different, and your Operations Manual is the only authoritative source for this kind of information. Sure, general rules-of-thumb could have been included in the program, but for your plane would you want a rule-of-thumb (abbreviated R.O.T.) calculated to sixteen decimal places? NAVPROGseven / Aircraft Data Page 14 NAVIGATION ========== Using the program you simply enter the number of check- points you'll be using, then the identifiers for those check- points. If the route is one that you expect to fly again you can save it for future use. Note that the checkpoint data is not saved but rather index numbers that allow the computer to find the data in the main file at a later date. This way if you update checkpoint data, the next time you use the stored flight the new data will automatically be picked up. Of course, if in the meantime you've deleted one of the checkpoints, the program will abort and return you to the menu. Regardless, you will be asked to verify that the route of flight is correct before calculations begin. Next you would enter your aircraft's N-number, the Flight Service Station you'll close your flight plan with, and the winds at each checkpoint. Of course winds at your departure and destination should be surface winds, while winds aloft should be used enroute. Surface winds and winds aloft may be obtained from your FSS, the NWS, or thru an online service such as CompuServe or others. To enter no-wind for a checkpoint you can enter '0,0' (or a comma by itself followed by a carriage return gives the same result). The computer will then ask for your cruising altitude, true airspeed, fuel consumption & fuel-on-board. The computer will show the 'standard' situation you entered with the aircraft data, and by simply hitting a carriage return for each of these questions the standard data will be used, or you can deviate by entering new data for the flight. Note that the computer does not adjust your true airspeed or fuel rate when you change altitude, nor does it take into account outside air temperature. While this could be done using some general rules-of-thumb, it's best that you refer to the Operations Manual for your plane and enter either the book values or values based on your experience. After you enter your cruise altitude the computer uses the departure elevation to calculate your climb profile, and the destination elevation to figure the descent profile. Note that during your climb to altitude the groundspeed printout is the average for the entire leg, taking into account your climb groundspeed (if you haven't reached altitude), cruise groundspeed (if you reach altitude before the checkpoint), and wind. The climb airspeed is an average based on the normal climb data, and CAS is based on your altitude on a standard day. These are guidelines, not hard numbers -- double check the Operations Manual for your plane. NAVPROGseven / Navigation Page 15 The computer then checks your cruising altitude with the elevation for each of your checkpoints enroute. If your cruise altitude brings you less than 1,000 feet AGL at any checkpoint the computer will caution you. Just because the computer clears this check DO NOT ASSUME THAT THIS IS A SAFE CRUISING ALTITUDE!!! The computer is only checking SURFACE ELEVATIONS, ONLY AT THE CHECKPOINTS YOU SPECIFIED, and ONLY AT THE CHECKPOINT ITSELF, NOT IN BETWEEN. The machine has no way of knowing if the elevation you originally entered was correct. It also has no way of knowing that between the two checkpoints there is a 14,000 foot mountain and that there's a broadcast tower on top of the mountain! CHECK YOUR CHARTS and know your clouds -- steer clear of cumulus granite and stratus erectus! In the fuel column a single hashmark will appear if fuel reserves are less than 45 minutes (below IFR and VFR night minimums), and a double hashmark signifies that less than 30 minutes of fuel remain (below VFR minimums). If the hashmarks appear you should plan to make an earlier fuel stop. It's usually inefficient to climb more than 10 minutes for each hour of estimated time enroute unless good tailwinds and high altitude cruising efficiency offset the fuel and time used to climb. With NAVPROGseven you can cycle thru the flight as many times as you wish, plugging in new variables and printing out the best flight profiles at the end of each cycle -- comparing fuel vs. time vs. dollars in order to get the best use out of your airplane. NAVPROGseven / Navigation Page 16 AUTOMATIC ROUTE PREPARATION =========================== Enter your point of departure and your destination and this program scans the database, selecting the checkpoints along the way that most closely follow a great circle route. The program automatically prepares several alternate routings for you to choose from, and with each pass the checkpoints are closer and closer together. If needed you can enter a specific checkpoint to be flown over (located to one side of a restricted airspace, let's say) and the computer will first route you to that checkpoint before turning you towards your destination. The sharper the dog-leg however, the longer the time required to calculate the route since more of the database must be repeatedly scanned. This program will not tell you the 'best' route to fly, but it will give you several logical alternatives. Military Operation Areas, large bodies of water, restricted & prohibited airspace are items the computer has no knowledge of. If your 172 gets intecepted by an F-16, don't tell them, "NAVPROG said this was the best route to fly", and expect to get off! On the other hand, NAVPROGseven is being used by several Coast Guard helicopter crews around the country, and I actually got a call one day at work from an Air Force general in Washington wanting a couple enhancements.... so who knows. The first pass through the database will give you the most direct route -- the fewest checkpoints and the longest leg lengths. Each subsequent pass will supply more and more intermediate checkpoints from your database with shorter and shorter leg lengths, all the while trying to stay as close as possible to the great circle between the last checkpoint and your destination. The more checkpoints, the more zigs and zags. From the possible routes, you must take into consideration the reception range of your navigation equipment, which is of course affected by your cruising altitude, station power, obstructions, etc, and how direct you wish to fly given these parameters without investing in an inertial navigation system for your Cub. NAVPROGseven / Auto Route Page 17 NAVIGATING A PRE-PLANNED ROUTE ============================== Any routings you generate using NAVPROGseven may be saved for use again at a later date. Only the routing information is saved, while flight particulars such as aircraft used, flight conditions, et cetera, are entered individually for each flight. Multiple routes between two points are also allowed, such as BEH to LUK via GSH versus BEH to LUK via SBN. The program will automatically distiguish routes based on the different VORs used as the first checkpoint after departure. If the first checkpoint is not a VOR, the "via" field remains empty. If neither of these techniques is suitable to uniquely identify a particular routing you can manually override the "via" information with any three letter code of your choosing. For example, you could call the first routing "RT1", the second "RT2", etc. When you choose to fly a pre-stored route the program retrieves the checkpoints you had saved earlier. If the check- point data has been revised the new data is automatically used. If the checkpoint data has been deleted since the last time the route was flown, the program will abort and return you to the menu. A printout can be obtained of all routes on file including all RNAV cross-references. SORT AND PRINT DATA ON FILE =========================== The sort program uses a Schell-Metzner sort routine to arrange the airport/navaid data on file into easy-to-use printouts. The data on file can be printed out by Identifier; by State & Ident; by State & City; by State, Facility & Ident; or unsorted straight from the file. NAVPROGseven / Pre-Planned Routes Page 18 PROGRAM SPECS AND NOTES ======================= Data for each airport, navaid, facility & checkpoint is stored on random file AIRPORTS.RND, five to a sector. A random index, AIRINDEX.RND, holds just the identifiers for each checkpoint and tells the computer the relative position of each sub-sector of data in the main file. RNAVLIST.DAT is a sequential file that saves the fixes you use in the RNAV mode. The primary database is contained in these three files which are constructed and maintained by AIRINPUT.BAS (RNAVREF.BAS automatically updates & maintains the RNAVLIST.DAT file after each flight). For maximum speed in retrieving airport and navaid data, the entire index is read into memory rather than doing repeated disc accesses. The standard 256K of RAM in the 150 will handle several thousand checkpoints. It should be noted that NAVPROGseven was designed for the general aviation pilot. This is not to say that you have to stick to one region of the country or stay within a thousand miles of home. No way. But by the same token, you're not Pan Am and this isn't an IBM Series 38. NAVPROGseven has an upper limit of 5400 miles for any given great circle computation. Since most flights tend to radiate out from one's home base, some pilots have chosen to set up separate data discs for flights east and west (or north and south) of home. Normally this was done because earlier machines only had 64K of memory and couldn't hold the entire index at once. This should be no problem on the HP-150. However, if you decide to do this: 1) make sure that all data files including your aircraft data and file DISKBID.DAT are copied over to your new data disc. 2) if divided between north & south data, provide some overlap to the north on your 'Southern' disc. Great circle routes north of the equator are always bowed towards the north pole. 3) as you edit your database, always delete unneeded checkpoints before adding new ones to make the most efficient use of disc and memory space. NAVPROGseven / Program Specs Page 19 AIRCRAFT.BAS takes data for each aircraft you fly and stores it in separate sequential files with the plane's N-number as the filename. Two aircraft, N73116 and N81259, are on file, with which you can experiment. ROUTINGS.DAT is an index of routes you have saved for later use -- it is created by AIRROUTE.BAS and called by OLDROUTE.BAS. The individual routes are stored in separate sequential files; i.e., information about a flight from Benton Harbor to Cincinnati Municipal (Lunken Field) is stored in file BEH.LUK. A file FLIGHT.SEQ is created temporarily by AIRROUTE.BAS or OLDROUTE.BAS to pass the file locations of the current route of flight to NAVPROG7.BAS and then to RNAVREF.BAS after which it is erased. RNAVREF.BAS looks at the route of flight and searches RNAVLIST.DAT for any checkpoints that were entered using RNAV cross-bearings, if so they are printed on your flight log for in- flight reference. Why doesn't NAVPROGseven generate my FAA flight plan for me? A good question. In the very first, experimental and unpublished versions of this program I included just such a routine. Rather simple actually, but why stop at a flight plan? Why not dump right into the autopilot and we can all fly around like so many locomotives on rails? My feeling is that preparing one's own flight plan form gives you time to pause, reflect and review the upcoming flight. I love computers, but it is the captain who has the final word. Let the computer do the number-crunching it does so well, but don't let it become the de-facto pilot-in-command of your plane as well. NAVPROGseven / Program Specs Page 20